The present disclosure relates to a signal amplifier having inverted topology in a stacked common gate structure, which may be used for a radio frequency (RF) receiving terminal of an ultrawideband (UWB) communications system.
In general, as a demand for wireless communications and various other communications standards increases, demand for multiband transmitters and receivers capable of simultaneously processing signals within various bands in a single portable device has increased.
For example, the wireless local area network (WLAN) standard simultaneously uses the 2.4 GHz and 5 GHz bands, while domestic long term evolution (LIE) simultaneously uses the 300 MHz, 900 MHz, 1300 MHz, and 2.1 GHz bands.
Therefore, a device for transmitting and receiving multiband signals in a signal RF front-end module is required, and particularly, technology for processing various frequencies or a wideband frequencies using a single low noise amplifier (LNA) disposed at an initial stage of the receiver is required.
Meanwhile, the low noise amplifier supporting a concurrent dualband capable of simultaneously processing signals within two different bands or supporting wideband frequencies may have a cascode structure or a cascade structure.
Typically, since an amplifier having the cascode structure, a structure having two transistors stacked between a power terminal and a ground GND, has a single current path, it has an advantage in that current consumption is low. However, since it includes a common gate amplifier in which gain characteristics are poor and a common source amplifier in which gain characteristics are excellent, there is a need to improve gain characteristics when a common gate amplifier is used.
In addition, an amplifier having a cascade structure has a structure including amplifying units for at least four stages between an input terminal and an output terminal. Since the amplifying unit of each stage may be formed of the common source amplifier, the gain characteristics thereof are excellent. However, since the amplifying units of each stage consume a large amount of current due to two or more current paths, there is a need for improvement in terms of current consumption.
As described above, when a common gate amplifier having low current consumption is used, improvements of relatively bad gain characteristics are required.